Group communication refers to a mechanism for mutual communication between a group of user equipments (UEs). During group communication, only one UE in a group of UEs is allowed to speak, and the other UEs receive voice content of the speaking UE over a downlink. Currently, group communication is usually implemented using a group communications server. Each UE in a group of UEs establishes a signalling connection and a voice connection to a group server in order to implement group communication. The group communications server authorizes, using signalling, a UE to speak, and transmits downlink voices of the speaking UE to the other UEs in the group. When a UE needs to speak, the UE requests the group communications server for the floor using Session Initiation Protocol (SIP) signalling. Only after the group communications server gives the floor to the UE, the speaking UE can send voices to the other UEs in the group. Similarly, the group communications server instructs, using SIP signalling, the other UEs in the group to start to listen to the talk.
Among current implementation manners of group communication, the simplest implementation manner is to implement group communication using a same processing manner as that for normal voice communication. That is, each UE on an access network side requires a separate downlink voice channel for transmitting a voice message. Such a processing manner requires each UE to separately send a same voice message. Consequently, radio resources are wasted.